Piston cooling and lubricating system for engines.



H. LEM?. IISTON COOLING AND LUBRICATING SYSTEM FOI. ENGINES. APPLICATION FILED IIIAI I5, 1914.

IILIIIFIQM www@ IIGI.. 26, 1915.

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H. LEMP. i PISTON COOLING AND LUBRICATING SYSTEM FOR ENGiNES.

Patned 0%. 26, M15.

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Witnesses:

Erie, county of Erie,

HERMANN LEMP, OE' ERIE, PENNSYLVANIA, ASSIG-NOR T0 GENERAL ELECTRIC COMPANY, A. CORPORATIDN OF NEW YORK.

Specification of Letters Patent.

Patented @et 26, 1915..

Application led May 15, 1914. Serial No. 838,648.

To all whom 'it may concern Be it known that I, HERMANN LEMP, la citizen of the United States, residing at State of Pennsylvania, have invented certain new and useful Improvements in Piston Cooling and Lubricating Systems for Engines, of which the following is a specification.

'Ihe present invention relates to internal combustion engines and in particular to those operating on the high compression plan, although it is not necessarily limited thereto. of this type, the smaller sizes may be sufficiently cooled by means of the usual water jackets around the cylinders, but when the pistonsy assume substantial proportions it becomes necessary to cool them as well. This introduces certain problems, the solution ofv which forms the subject matter of the present invention.

For a'consideration of what I believe to be novel and my invention, attention is. directed to the accompanying description and claims appended thereto.

In the accompanying drawings which' illustrate one of the embodiments of my invention, Figure 1 is a view in side elevation of an engine and associated cooling and supply tanks, certain of said parts being in section; Fig. 2 is a partial plan view of the same with some of the parts removed to more clearly illustrate the construction, and Fig. 3 is a detail view of oneof the pistons.

3 indicates an internal combustion engine of any suitable construction. As shown, each cylinder 4 is provided with two oppositely moving pistons 5, shown in dotted lines Fig. 1, although the invention is not limited thereto. Such an arrangement, however, requires a somewhat more elaborate cooling system than where each cylinder has only one piston and I have, therefore, elected to illustrate my invention in this connection. The cylinders are, supported by a base 6 of any suitable construction which also carries the bearing support 7, Fig. 2, for the main crank shaft 8. The pistons are connected to the cranhsby connecting rods,

not shown, in the usual manner. The upper As is well understood `with engines piston of each cylinder is provided with a cross-heads are conduits for conveying coollng fluid, such as oil, to and from a chamber in the piston. The particular arrangestructed to prevent excessive leakages. The

casing is supported by feet from the upper wall of the engine base. The inlet chambers 1n the casing are connected to the manifold 15, Fig. 2, by pipes 16 and the outlet chambers by pipes 17 to the manifold 18, Fig. 2, the latter extending through the base of the engine and delivering the heated oil to the cooling coils 19. The cooling coils are 1ocated in a tank 20 containing water and are arranged in parallel relations as regards the How of fluid. Cooling water is admitted to the tank by the pipe 21 and discharged by the pipe 22. It will ordinarily be satisfactory to connect the pipe 21 to a water service main and let the water continuously flow through the tank. I have illustratetd a type of cooling means that is satisfactory for the purpose, but other forms of apparatus may be substituted therefor. It is also within the scope of my invention to combine the cooling means and supply tank in one structure as will be evident. Cooling iuid` is also supplied to the lower pistons by the pipes 23 from which it passes into the chambered head of each piston by the pipe 24 and escapes by the'pipe 25, the means for getting the fluid into and out of the piston chamber being similar in operation and general construction to the tubes 12 and 13 and casing 14. As this particular means forms no part ofthe present invention, it has not been specifically illustrated. The pipes 25 are also connected to the exhaust manifold 18. It will thus be seen that fluid flows in paral- `cross-head 9 moving `in guides 10. In the lel from the inlet manifold through both pistons in each cylinder to the exhaust manifold. In this manner the displacement of the tubes in one piston is balanced by the displacement in the other piston 180o apart and the resistance to flow is thereby reduced to a minimum. To further illustrate .this point, Where telescopic or trombone sliding tubes are used in a .piston cooling system, the stationary and moving tubes act like a pump without valves and cause relatively rapid movement yof the fluid, producing s l what is commonly called water hammer.

To avoid this the cooling means of the upper and lower pistons in one cylinder should be connected in multiple, or the cooling means n of a piston in one cylinder and that of a piston of an adjacent cylinder and displacedA should be connected in multiple,

which is the arrangement illustrated in the drawings.

Fluid is supplied to the inlet manifold by the positively driven rotary circulating pump 26, shown in dotted lines' in Fig. 2. It is shown in dotted lines because it is above the plane of the section on which the lfigure is taken. The pump is driven by the cam shaft 27 that actuates the valves, not shown, admitting fuel to the engine. Fluid is admitted to the pump by the pipe 28 from the supply tank 29, the latter being located at a point above th'e circulating pump so that fluid will flow by gravity thereto and thus avoid the necessity of priming the pump at starting. In specifying an elevated supply tank I mean one which is above the suction valve of the pump and not its position with respect to the engine. This arrangement is important because if the engine is started without the cooling system in operation the 'piston and cylinder will be seriously injured in a very brief time. Elevating the tank insures' the proper feeding of fluid to the pump without thought or attention on the partl of the operator.l Fluid after being properly cooled in the coils 19 in the tank' 2O flows by the vertical pipes 30 into the supply tank 2Q, thel ends of the pipes being slightly above the edge of the tank so that the operator can observe the amount of fluid flowing and thus quickly detect any substantial reduction in the amount discharged. If4

ing liuid to and from incassa through a filter 34 located in'a recess or sump in the crank casing which forms a supply chamber. The cylinder is provided with the necessary valves and its plunger 35 is actuated by a 'lever 86 fulcrumed on the engine frame and vibrated by the eccentric 37, the latter being mounted on the main shaft. Leading from the discharge valve of the pump is a lubricating manifold 38 which supplies lubricant through orifices 39 in the bearing supports 7 to the main shaft. As is usual, the shaft is provided with passages through which lubricant liows to the various bearings of the connecting rods. The cylinders may and usually will be lubricated by splash from the oil in the crank casing as the cranks-revolve. Connected to the lubricating or oiling manifold 38 is a by-pass 40 which continuously discharges lubricant to the supply tank 29. In the by-pass is an adjustable valve 41 which is held in adjusted position by any suitable means, suchas the spring 'finger 42 engaging a notch in the hand wheel.

Theoretically there should be no leakage from the piston cooling system into the crank chamber, but practically there is always some. If no leakage existed the pipes 30 would deliver a constant amount of liuid to the supply tank 29 and this same amount would ow to the circulating pump and complete the cycle. Under these theoretical conditions the overiiow pipe 31 would be unnecessary. Since, however, leakage is bound to exist the by-pass 40 is provided around the lubricating pump, which by-pass always delivers an amount of fluid to the tank that is greater than any permissible leakage from the cooling system. This requires an overow from the supply tank to the crank chamber unless fluid is to be bailed from the former and conveyed to the latter which would require constant attention on the part of the operator. The overflow and its connected pipe entirely obviate this and excess fiuid is automatically returned to the crank chamber for further use, and besidesthis a constant head of oil is always available for the circulating pump. By providing a lubricating pump of proper size and adjust. ing the by-pass valve 41 there will always be an excess of fluid over the maximum demands for normal operation delivered to the supply tank but the level therein will never change. When there is an appreciable fall ing off in the amount of fluid discharged by the pipes 30, indicating excessive leakage through some of the pipes conveying coolthe pistons, the engine should be shut down and the trouble corrected, since otherwise the engine will be seriously injured and possibly one or more pistons and cylinders ruined.

I have specifically described my invention in connection with piston cooling means,

but it may be utilized to supply fluid to cooling chambers in the cylinders. I have utilized the lubricating pump to convey fluid from the crank chamberto the supply tank because in this manner I am enabled to dispense with an extra# pump, but in the broader aspect my invention is not so limited.

By using the same fluid to cool the pistons that is used to lubricate the various shaft bearings and other surfaces, and permitting all leakages to collect in the crank chamber, I avoid the complication which would naturally arise if two fluids Were employed which have to be separately confined.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus Winch I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is:-

l. In combination, an engine having a chamber through which cooling fluid is cir- .culated and a supply chamber, a supply tank, a circulating pump receiving fluid from the tank and delivering it to the first named chamber, means for conveying the fluid therefrom back to the supply tank, said means including a cooling device, a pump receiving fluid from the second named chamber and conveying it to the supply tank, and a means for maintaining a constant fluid level in the tank and returning the excess to said second named chamber.

2. In combination, an engine having a fluid cooled piston, a supply tank, a circulating pump which receives fluid from the tank and delivers it to the piston, means for conveying the fluid from the piston to the tank, means other than said circulating pump for automatically supplyingfluid to the tank, and means for maintaining a constant fluid level in the supply tank.

3. In combination, an engine having a fluid cooled piston, a supply tank, a-circulating pump which receives fluid from a tank and delivers it to the piston, means for conveying the fluid from the piston to the tank, a pump which receives Huid from the crank casing of the engine and delivers it to the tank, and an overflow means for maintaining a constant fluid level in the tank and returning the excess to the crank-chamber.

4. In combination, an engine having a chamber through which cooling fluid is circulated, a supply tank, a circulating pump receiving fluid from the tank and delivering it to the chamber,means including a cooling device that receives fluid from the chamber and conveys it to the supply tank, means for cooling said device, a pump which receives fluid from the crank chamber of the engine and conveys it to the supply tank, and a means for maintaining a constant level of fluid in the tank and returning the excess to said crank chamber.

5. In combination, an engine having a fluid cooled piston,- a supply tank, a circulating pump rece1v1ng fluid from the tank and delivering it to the piston,a cooling coil that receives fluid discharged from the piston and conveys it to thesupply tank, a tank containing cooling liquid in which the coil is located, a pump thatreceives fluid from the crank chamber and delivers it to the supply tank, and an overfl'ouT for the supply tank that discharges'qinto thecrank chamber.

6. In combination, an engine having a fluid cooled piston, crank shaft and bearings therefor, a supply tank, a circulating ump receiving fluid from the tank and deivering it to the piston, means including a cooling device that receives the fluid from the, piston and conveys it to the tank, a lubricating pump that receives fluid from the crank-chamber of the engine and supplies a portion of it to the engine bearings and the balance to the supply tank, and means for maintaining a constant fluid level in the supply tank and returning the excess to the crank-chamber.

7. In combination, an engine having fluid cooled pistons, a supply tank, a circulating pump, a manifold that receives fluid from the pump and discharges it in parallel to the pistons, a second manifold that receives fluid in parallel from the pistons, a cooling means through which fluid from the second manifold passes on its Way to the supply tank, and means for maintaining a constant fluid level in the supply tank.

8. In combination, an engine having fluid cooled pistons, a supply tank, a circulating pump arranged below'the level of the fluid in the tank, a manifold that receives fluid from the pump and delivers it to the piston in parallel, means receiving the fluid from the pistons and returning it to the tank, a means independent of the pump for supplying fluid to the tank, and means for maintaining a constant fluid level. in the tank.

9. In combination, an engine having oppositely moving chambered pistons in each cylinder, a circulating pump, an elevated supply tank that feeds fluid by gravity to the pump, a manifold connected to the pump which supplies fluid to all of the pistons in parallel, a second manifold that collects fluid from all of the pistons, a cooling means receiving fluid from the second manifold and delivering it to the supply tank, means for supplying an additional amount of fluid to the tank, and means for maintaining a constant fluid level in said tank.

10. In combination, an engine having a fluid cooled piston, a supply tank, a circu- Limes@ i lating pump which maintains a continuous level in the supply tank and returning the circulation of fluid through the tank and pisexcess to said chamber.

l0 t0n, a second pump which continuously de- In .Witness whereof7 l' have hereunto set livers anamount of fluid to the supply tank myhand this eleventh day of Maty, 1.914. in excess of the permissible leakage in the HERMANN LEMP. cooling system, a, chamber in communication Witnesses: with the suction side of the second pump, ROAN HUHN, and means for maintaining a constant luid O. T. FoUcHn.

Gomesy of this pate-nt may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 

